The number of workers employed in the public sector has fallen by almost 660,000 since the coalition Government came to power, with further cuts being planned, according to new research.

The GMB union described the cuts as the most "savage decimation" of public services ever seen.

Almost 300,000 of the reduction have been in local government, a "considerably higher" number than original estimates, it said.

The GMB warned of fresh cuts next year as health authorities and councils face "significant" new budget challenges.

The report was published as Newcastle City Council in the North East warned of at least 1,300 job losses as it looks to reduce its budget by £90 million.

Most of the fall has been as a result of job cuts, although some posts have been privatised or moved out of the public sector from schools and colleges to academies, said the GMB.

The union said the biggest percentage fall in the number of public sector employees has been in the South West, at 86,000 (15.7%), with other falls including 84,000 in London, (10.1%), 80,000 in the South East (11.1%), 77,000 in the North West (10.6%), 59,000 in the East of England (2.4%), 56,000 in the West Midlands (10.6%), 54,000 in Yorkshire and The Humber, (9.6%), 45,000 in Scotland (7.2%), 43,000 in the North East (14.5%), 42,000 in the East Midlands (10.4%), 18,000 in Wales (5.2%) and 11,000 in Northern Ireland (4.8%).

Most of the job losses arose from freezing vacancies, redundancies and natural wastage as a result of budget cuts, said the GMB.

GMB national officer Brian Strutton said: "Plainly this Government has engineered the most savage decimation of public services ever seen.

"As the Bank of England Governor, Mervyn King, has said, public service workers carry no blame at all for the financial crisis, yet they are carrying most of the burden while banks are bailed out, utility prices spiral up and company bosses trouser ever bigger pay packets.

"The scale of public sector job losses so far now outstrips the last two recessions in 1982-87 and 1992-97 to stand at a shocking 659,000. Of this number, over 350,000 are from priority services like health, social services, education and the police."